Silver nitrate holder for process cameras



May 12, 1931 H. R. HAYS SILVER NITRATE HOLDER FOR PROCESS CAMERAS Filed Oct. 31, 1929 INVENTOR "Kc ATTORNEY,

UNrrs PTET OFFICE HOWARD R. HAYS, OF PHILADELPHIA COUNTY, PENNSYLVANIA, ASSIGNOR TO HOVIARD S. LEVY AND LIONEL F. LEVY, BOTH OF PHILADELPHIA, PENNSYLVANIA SILVER NITRATE HOLDER FOR PROCESS CAMERAS Application filed October 31, 1929. Serial No. 403,686.

This invention relates to a device known in process photography and specifically in connection with process cameras, as a trough for silver nitrate.

Troughs for silver nitrate are used to insure plate holders, for wet plates, against deterioration from silver nitrate drippings, the latter from the face of the plate draining downwardly by gravity into a cavity in the trough.

In process work many sizes of plates are used at different times in the same holder and, as a consequence, the trough supporting the plate from underneath is detachable and adjustable in the frame of the holder to substantially any predetermined elevation. Both the plate holder and trough in the past have been constructed entirely of wood, the trough being simply provided "ith a tongue at each end which is accommodated in any one of a series of grooves disposed one above the other along each upright side frame. Ithas been found that the connection made by these grooves and tongues, when subjected to moisture and constant wear, soon becomes loosened and has a tendency to throw the trough out of parallel with the screen.

In actual construction, plate holders include a door which heretofore retained the trough in place in the slots or grooves which are disposed at right angles to the two upright strips of the holder. After the connection between the trough and holder has become loosened, as just described, the move to open the door is very apt to cause the trough, under the Weightof the plate, to slip out of place.

With the foregoing in mind, it is the purpose of the present invention to avoid as far as possible any chance of the trough working its own way out of its side supporting frames and at the same time, to make it unnecessary to rely upon the door to keep the trough in its proper position in the holder. I accomplish this purpose by means of thearrangement and combination vof parts hereinafter described in the speci-' fication, set forth in the claims and illustratively exemplified in the accompanying drawings, in which, Figure l is a perspective view of the back of the plate holder, the latter being provided with trough and associated parts; Figure 2 is a perspective view of one end of the trough; Figure 3 is a perspective view of one of the metal supporting strips for the sides of the holder; Figure l is a perspective view of one end of a trough showing a locking element different from that illustrated in Figure 2; Figure 5 is a sectional view taken along an upright line 55 of Figure 1; and Figure 6 is a substantially longitudinal sectional view of the trough, illustrated in Figure l, showing the lock connection between the holder and trough.

Referring to the drawings, 10 denotes a plate holder for a process camera compri ing bottom frame 11, upright side frames 12 and top frame 13. Plate holders of this character are either equipped with a dark slide, door or curtain M. The inner face of each upright side frame 12 is'provided with a partition strip 15 which extenos from bottom to top of the frame, and which at its lower endis cut away to accommodate a metal supporting strip 15. Each metal strip 15 is L-shaped in transverse section, as illustrated in Figure 6, the upright arm of the L being substantially square in its transverse section and divided into a series of forwardly inclined tongues 16 and intermediate grooves 16. The angle of the tongues 16 and grooves 16 is acute to the axis of the strips 15 and the grooves 16 at the lower end are spaced a greater distance apart than those farther up the strio, as illustrated in Figure 3. The base piece of the L fills in the space left by the cutout portion of the partition strip 15 and virtually forms a continuation thereof. It will be seen especially in Figure 6, that the upright arm of the L-shaped strip 15 while it is square in transverse section, the side thereof towards the base, does not project to the plane of the rearward face of the base and as a consequence, a shoulder 17 is provided throughout the entire length of the strip 15' just beyond or rearwardly of the higher ends of the grooves 16 and tongues 16; in fact,

the trou h." The actual the bottom wall of the grooves 16 is sub stantially a continuation of the shoulder 17. Gpposite ends of the metal strip 15 are drilled to receive wood screws 18, which are driven into the frame work 12 at the bottom of the cutout of the partition strip The trough 18 comprises a straight length of wood or other suitable matei'rial arranged so as to bring its broader faces parallel with the front and rear of the plate holder. The upper side of the'trough 18 is beveled from a. line short of the rear wall downwardly towards the front face to guide the drippi. towards one face of ti trough. Arranged at spaced intervals on the inclined or beveled surface 18 are metal clips 19 comprising flat mid portion having oppositely projecting ends 20 and 21, theformer being driven into the wood at the angle of the bevel and top surface of the trough and the latter end comprising a sector shaped tip projecting upwardly from the lower level of the beveled side and disposed'flush with the rear face of trough comprises a recess 19 cut into front face of the wood strip to receive the drippings' from above, the recess being about midway of its height, as shown in Figure 2, or in the eled top 18 as illustrated in Figure l, the rear wall 20 of the recess 19 being inclined inwardly from a line just below the low line of the bevel18, the bottom and forward walls of the recess forming pocket into which the dripping nitrate of silver is drained and held.

As previously stated, the ends of the trough 18 are removably suported in the inclined grooves 16 of the strips 15 on upright side frames 12 of the plate holder 10, and according to the present invention the means used to provide an eficient joint, according to the embodiment in Figure 3, con1- prises metal end pieces 22, each of which ineludes an L-shaped piece of material, of a length about equal to the height of the trough 18. One side 22 of the piece'22 is rovided on its outer surface with a ton ue p. 7 7 D 23 which is fixed in a groove 23 disposed in the end of the wood trough. The other side 24 of the piece 22 is flush withthe rea' face of the trough and projects longitudinally thereof. The side 24 virtually becomes a flange and from the upper end thereof a flange 25 projects, which is integral with and extends across the inner face,

of the side 22" opposite the tongue 23 at an acute angle which brings it to the free end of the side 22 about midway of its height. This construction when viewed from the end of the trough is substantially an inverted V-shaped projection or tongue, the part or flange 24- thereof,being directly upright while the tongue 25 projects in a forwardly and downwardly direction at an acute angle to the free end of the side 22.

incense The angle of the flange 25 with respect to the upright axis of piece 22 is the same as the angle of any of the grooves 16 in the strips 15, so that in order to support the trough thereon, the flanges 25 are merely introduced into corresponding grooves 16 from the rear of the plate holder and allowed to project therein until the sides or flanges 24 are brought into contact with the rear faces ofthe strips 15 and the ends of the rear arm or sides 2 l'abut the shoulders 17, as illustrated in Figure 5.

In the form of my invention illustratively exemplified in Figures l and 6, the connec tions 22 at the ends ofthe trough comprise plates 26 set in recesses 27 in the rear face, the outer end of each plate projecting beyond theend of the trough to form an upright arm or flange 28 which abuts the shoulder 17 and which extends above the upper end of the plate 26, and at a point above the upper surface of the trough is bent downwardly and forwardly at anacute angle to form a tongue'29 adapted to fit tightly in a groove 16 ofthe supporting side strip 15.

t will be clear that as portions of the the strips 15 wear away, the wedging action of the joints will not be changed as long as any of the material of the flanges remain. cour e, the deterioration of the metal end pieces 22 will be much less rapid than that of the wood tongues now in use.

To arrange thetrough in position, the proper elevation of the trough is ascertained and tongues 25 and 29 are locked in the grooves 16 of the side pieces 15'. As a re sult, the trough will not rock regardless of how loose the end pieces on the trough fit the grooves, nor will the troughbe dependent upon the door for support against possible disengagement of the connecting means.

Having now described my invention, what I claim and desire to secure by Letters Pat ent of the United States, is:

1. The combination of a plate holder and a wet plate carrier of the 7 character described, and'compleinentary inclined tongue and groove supporting means between the plate holder and carrier to support the latter.

2. The combination of a plateholder having inclined groovesfon its opposite inner projections, each thereof having one arm to be inserted into any one of the inclined groves of an insert, the other arm being brought into engagement with one side of said insert.

4:. A supporting device for the silver nitrate solution trough of a plate holder, comprising a pair of metal insert members having a plurality of corresponding grooves directed towards each other across the holder, each groove being disposed at the same acute inclination to the upright axis of the holder and spaced at varying distances from each other, and metal end pieces for opposite ends of the trough, each piece having an upright flange to engage the adjacent side of the metal insert and a downwardly and outwardly directed flange to be introduced into a complementary groove in the insert to removably support the end of the trough.

5. As an article of manufacture, a'metal end piece for supporting the end of a silver nitrate solution trough in a plate holder, comprising a flat plate and an upright projection at the upper end bent downwardly and forwardly to form an acute angle with the said plate portion.

6. As an article of manufacture, a metal insert for the sides of a plate holder to support the end of a silver nitrate solution trough, comprising a bar having a plurality of uniformly spaced projections at varying heights, the adjacent parallel transverse walls of the projections being disposed at an angle to the upright axis of the bar, and the bottom wall of the grooves projecting beyond the latter to form a flange.

In testimony whereof I afiix my signature.

HOWARD R. HAYS. 

